Helium?!?!?

its come in my mind before, has anyone ever tried pumping up their tires/tubes with helium? would it make your bike FEEL lighter? it keeps on coming back to me, so i wanna try it one day... would it work?

Mythbusters did an episode with helium-filled footballs. It didn't make any significant difference. Still, it would be interesting to calculate how much the volume of air in a bike wheel weighs, then figure out how much the volume of helium would weigh at the same pressure. I suspect it's not more than a few grams, but that's enough for a few weight weenies to give it a shot.